UH-1M Components

3. Elevator: The synchronized elevator is
located on the tailboom. It is connected by control tubes and mechanical linkage to the fore and
aft cyclic system. Fore and aft movement of the cyclic control stick will produce a change in
the synchronized elevator attitude. This improves controllability within center of gravity
range.

6. Transmission: The transmission is
mounted forward of the engine and coupled to the power turbine shaft at the cool end of the
engine by the main drive shaft. The transmission is basically a reduction gearbox, used to transmit
engine power at a reduced rpm to the rotor system. A freewheeling unit is incorporated in
the transmission to provide a quick disconnect from the engine if a power failure occurs.
This permits the main rotor and tail rotor to rotate in order to accomplish a safe
autorotational landing. The tail rotor drive shaft is on the lower aft section of the
transmission. Power is transmitted to the tail rotor through a series of drive shafts
and gearboxes. The rotor tachometer generator, hydraulic pumps, and main dc generator
are mounted on and driven by the transmission. A self-contained pressure oil system is
incorporated in the transmission. The oil is cooled by an oil cooler and turbine fan. The
engine and transmission oil coolers use the same fan. The oil system has a thermal bypass
valve which causes the oil to bypass the cooler when the oil is below operating
temperature ( approximately 54°C ). An oil level sight glass, filler cap, and chip
detector are provided.

8. Crew Doors: The cockpit doors are formed aluminum
frames with transparent plastic windows in the upper section. Ventilation is supplied by
the sliding panels in the windows. Cam-type door latches are used and doors are equipped
with jettisonable door releases.

9. Cabin Doors: Two cabin doors are formed aluminum
frames with transparent plastic windows in the upper section. The doors are on rollers and
slide aft to the open position allowing full access to the cargo areas. An open door lock
is provided to secure the door in the aft position.

11. Tailboom: The tailboom section is bolted to the
aft end of the fuselage and extends to the aft end of the helicopter. It is a tapered,
semi-monocoque structure employing skins, longerons, and stringers. The tailboom supports
the tail rotor, vertical fin, and synchronized elevator and houses the tail rotor
drive shaft and some electronic equipment.

13. Engine Oil Tank: The dry sump pressure type oil
system is entirely automatic in its operation. The system consists of an engine oil tank
with de-aeration provisions, thermostatically controlled oil cooler with by-pass valve,
pressure transmitter and pressure indicator, low pressure warning switch and indicator,
sight gages, and oil supply return vent, and breather lines. Crashworthy protection for
the engine oil system is provided by self-sealing breakaway valves installed on the engine
oil inlet, outlet and breather hoses. Drain valves have been provided for draining the oil
tank and cooler. Pressure for engine lubrication and scavenging of return oil are provided
by the engine-mounted and engine driven oil pump.

14. Main Rotor Hub and Blade: The main rotor is a two
bladed, semi-rigid, see-saw type. The two all metal blades are connected to a common yoke
by blade grips and pitch change bearings with tension straps to carry centrifugal forces.
The rotor assembly is connected to the mast with a bearing mounted trunnion and secured to
the mast with a nut. The nut has provisions for hoisting the helicopter. A stabilizer bar
is mounted on the trunnion 90 degrees to the main rotor. Blade pitch change is
accomplished by movements of the collective and cyclic controls. The main rotor is driven
by the mast through the transmission.

19. External Power Receptacle: The external power
receptacle transmit the ground power unit 28 vdc power to the power distribution system.

20. Battery: The battery supplies 24
vdc
power to the power distribution system when the generators and external power receptacle
are not in operation.

22. Landing Light: The landing light is flush mounted
to the underside of the fuselage. It may be extended or retracted to improve forward
illumination.

23. Crew Doors: The cockpit doors are formed aluminum
frames with transparent plastic windows in the upper section. Ventilation is supplied by
the sliding panels in the windows. Cam-type door latches are used and doors are equipped
with jettisonable door releases.

24. Searchlight: The searchlight is flush-mounted to
the underside of the fuselage. The light can be extended and retracted for search
illumination. At any desired position in the extend or retract arc, the light may be
stopped and rotated to the left or right.

25. Tail Rotor: The tail rotor is a two-bladed,
semi-rigid delta-hinge type. Each blade is connected to a common yoke by a blade grip and
pitch change bearings. The hub and blade assembly is mounted on the tail rotor shaft with
a delta-hinge trunnion to minimize rotor flapping. Blade pitch change is accomplished by
movement of the anti-torque pedals which are connected to a pitch control system through
the tail rotor ( 90 degree ) gearbox. Blade pitch change serves to offset torque and
provide heading control.

27. Anti-Collision Light: The anti-collision light is
located on the top aft fuselage area.

29. Cabin Ventilators: The ventilating system
consists of four independently controlled exterior air scoop ventilators. Two single
orifice air scoops are located on top of the cockpit section, and two double orifice air
scoops are on top of the cargo/passenger section of the cabin. The amount of air entering
the cabin through the ventilators is regulated by the butterfly valve control.

31. Landing Gear: The main landing gear consists of
two arched crosstubes mounted laterally on the fuselage with two longitude skid tubes
attached to the crosstubes. The skid tubes are made of aluminum and have steel skid shoes
attached to the bottom to minimize skid wear.

32. Position Lights: Two green position lights are
mounted on the left side of the fuselage. One just below the cabin door and the other just
above the cabin door. A white position light is also installed on top of the fuselage on
the right side.

34. Position Light: White position light mounted on
the right side of the tailboom below the vertical fin and aft of the antenna.

41. Tail Skid: A tubular steel tail skid is installed
on the aft end of the tailboom. The skid acts as a warning to the pilot upon an
inadvertent tail-low landing and aids to protect the tail rotor from damage.

42. Position Light: White position light mounted on
the left side of the tailboom below the vertical fin and aft of the antenna.

47. Position Lights: Two red position lights are
mounted on the left side of the fuselage. One just below the cabin door and the other just
above the cabin door. A white position light is also installed on top of the fuselage on
the left side.